One thing you may want to keep in mind is that the 4Runner's straight tailpipe will heat up whatever you put on this hitch-mounted cargo carrier. I thought about getting a hitch-mounted cargo carrier, but when I read the product description, it said not to use it on a vehicle with a straight tailpipe because it could literally melt some of your cargo.
I think there may be a post on here where that actually happened to someone. One solution I have been contemplating is an attachment that I have seen in Cabela's catalog (I don't see it on their website) which fits into the hitch receiver and raises the cargo carrier much higher. I believe it is designed to allow for a greater departure angle (clearance) for the cargo carrier, but it may solve the straight tailpipe heat problem as well.